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mission of acquired characters must be admitted to occur. He cited several 

 examples which seemed to support this view, and especially discussed the 

 sucker in leeches as an adaptation to parasitism and the evolution of the 

 chambered shell in a series of fossil Cephalopods. — Professor O shorn re- 

 marked in criticism of Dr. Graf's paper that this statement does not 

 appear to recognize the distinction beetween ontogenic and phylogenic 

 variation, or that the adult form of any organism is an exponent of the stirp, 

 or constitution. The Environment. If the environment is normal the adult 

 would be normal , but if the environment (which includes all the atmosphe- 

 ric, chemical, nutritive , motor and psychical circumstances under which the 

 animal is reared) were to change , the adult would change correspondingly ; 

 and these changes would be so profound that in many cases it would appear 

 as if the constitution , or stirp , had also changed. Illustrations might be 

 given of changes of the most profound character induced by changes in 

 either of the above factors of the environment, and in the case of the motor 

 factor or animal motion, the habits of the animal might, in the course of a 

 life time, profoundly modify its structure. For example, if the human infant 

 were brought up in the branches of a tree as an arboreal type instead of as 

 a terrestrial, bi-pedal type, there is little doubt that some of the well known 

 early adaptations to arboreal habit (such as the turning in of the soles of 

 the feet, and the grasping of the hands) might be retained and cultivated, 

 thus a profoundly different type of man would be produced. Similar changes 

 in the action of environment are constantly in progress in nature since there 

 is no doubt that the changes of environment and the new habits which it 

 so brings about far outstrip all changes in constitution. This fact which has 

 not been sufficiently emphasized before, offers an explanation of the evi- 

 dence advanced by Cope and other writers that change in the forms of the 

 skeletons of the vertebrates first appears in ontogeny and subsequently in 

 phylogeny. During the enormously long period of time in which habits in- 

 duced ontogenic variations it is possible for natural selection to work very 

 slowly and gradually upon predispositions to useful correlated variations, 

 and thus what are primarily ontogenic variations become slowly appa- 

 rent as phylogenic variations or congenital characters of the race. 

 Man, for instance, has been upon the earth perhaps seventy thousand years; 

 natural selection has been slowly operating upon certain of these predispo- 

 sitions, but has not yet eliminated those traces of the human arboreal habits, 

 nor completely adapted the human frame to the upright position. This is as 

 much an expression of habit and ontogenic variation as it is a constitutional 

 character. Very similar views were expressed to the speaker in a conver- 

 sation recently held with Professor Lloyd Morgan, and it appears as if a 

 similar conclusion had been arrived at independently. Professor Morgan 

 believed that this explanation could be applied to all cases of adaptive mo- 

 dification , but it is evident that this cannot be so because the teeth here 

 undergo the same progressively adaptive evolution along determinate lines 

 as the skeleton and yet it is well known that they do not improve by use, 

 but rather deteriorate. Thus the explanation is not one which satisfies all 

 cases but it does seem to meet, and to a certain extent undermine, the special 

 cases of evidence of the inheritance of acquired characters, collected by Pro- 

 fessor Cope in his well known papers upon this subject. — C. L. Bristol, 

 Secretary. 



